Every Ebola survivor treated in the United States has suffered from at least one chronic health issue for months following their release from the hospital, according to a report published Dec. 17 in the New England Journal of Medicine.

These issues affected joints, muscles, moods and even the senses, as some patients have reported blurry vision and hearing loss, researchers found in a survey of eight Ebola survivors.

"The story is not over in Ebola virus patients once they're discharged and go home," said lead researcher Dr. Tim Uyeki, the clinical team lead for the Ebola response mounted by the U.S. Centers for Disease Control and Prevention. "They may suffer from a wide range of illnesses."

Eleven people wound up being treated for Ebola infection in the United States, and two of them died from the virus, Uyeki said.

Uyeki and his CDC team reached out to eight of the survivors in March, to see how they had fared after being discharged from the hospital. Some had been out for as few as four months, and some for as many as seven months. The ninth Ebola patient still was being treated at the time of the survey, and was not included.

The most common post-Ebola symptoms were joint pain, hair loss and lethargy, with six patients reporting each of these symptoms, the CDC researchers found.

Other symptoms, along with the number of patients who reported them, include:

Eye inflammation -- a condition called uveitis -- was the most serious post-Ebola symptom. "If untreated, that can lead to permanent vision loss," Uyeki said.

However, Uyeki said his team doesn't know if the patients still suffer from these problems, as there's been no follow-up survey performed.

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"Many complaints may be quite common, but the frequency and the duration of symptoms are unknown," he said. "Some of them may be permanent. For example, there could be permanent vision loss."

Ebola expert Dr. Lee Norman said he was not surprised that people suffer chronic symptoms after their infection has been cleared, but found the report "very helpful in terms of further defining the variety of symptoms that can persist."

Neither Uyeki nor Norman could say why Ebola is linked to these longer-term health problems. "The mechanics of why it affects the human body in these ways are nowhere close to being understood," said Norman, chief medical officer for the University of Kansas Hospital in Kansas City.

But Ebola is a hemorrhagic fever, meaning that it causes bleeding inside the body, and Norman explained that the symptoms in the report are very similar to those found in patients recovering from another hemorrhagic illness called Dengue fever.

"It wouldn't surprise me to see some of the same mechanisms of Dengue in Ebola," Norman said.

These patients are being treated on a symptom-by-symptom basis for their post-Ebola complaints by their regular doctors, Uyeki said.

The U.S. National Institutes of Health is mounting an extensive study in Africa that will provide even more information on the long-term health outlook for Ebola survivors, Norman and Uyeki said.

That survey will come on the heels of the 2014 West Africa outbreak, which was the largest Ebola epidemic in history. As many as 28,640 people were sickened by Ebola in the nations of Guinea, Liberia and Sierra Leone, and 11,315 died, according to the CDC. Guinea continues to struggle with a trickle of new cases, but Liberia and Sierra Leone have been declared free of the disease.

"It's encouraging there's an intense research effort going on in Africa, where there are a lot of recovering or recovered people," Norman said.